Somewhat similar to the RvR from Warhammer unsurprisingly, which was done really well imo, I am not a fan of PvP generally but that managed to draw me in and make it fun. Definitely worth a look I feel.

"Definition: Love is making a connection with another person against long odds." "Clarification: Love is making a shot to the knees of a target 300 kilometers away using an Aratech sniper rifle with a tri-light scope."-HK-47WoW Millionaire